Mining machine gathering head

ABSTRACT

A gathering head for a mining machine is positionable at a forward end of the machine. The gathering head includes a base, a back plate and sidewalls. The sidewalls are both tapered inwardly in the widthwise direction of the head from a forward end to a rearward end and outwardly relative to the base from a lowermost region to an uppermost region. Accordingly, the requirement for additional gathering arms at a base region of the head is avoided.

FIELD OF INVENTION

The present invention relates to a mining machine gathering headpositionable at a forward end of a mining machine, and in particular,although not exclusively, to a gathering head having a pair of end wallspositioned at the lengthwise ends of the head being shaped andconfigured to guide a flow of extracted material into and from thegathering head.

BACKGROUND ART

A variety of different methods and machines have been developed toextract minerals and other valuable materials at and below the Earth'ssurface. Such machines typically operate in mines at great depths.

In order to maximise excavation and mineral recovery efficiency, miningmachines have been developed for specific purposes. Whilst some machinesare configured exclusively to cut the mineral from a deposit or seam,other machines are configured to tunnel within the subterranean depth toeffectively create the mine and provide passageways for the mineralcutters. In particular, mobile mining machines have emerged assuccessful apparatus to both provide direct cutting at the seam and as ameans of rapid entry roadway development. Typically a mobile miningmachine comprises a rotatable cutting or mining head having cutting bitsprovided on rotating drums to contact the mineral face. The cutting headis conventionally mounted at a moveable boom so as to be adjustable inheight relative to the mine floor. As the cutting head is rotated andadvanced into the seam, the extracted mineral is gathered by a gatheringhead and then conveyed rearwardly by the mobile machine via conveyingapparatus to create discharged stock piles for subsequent extractionfrom the mine. Example gathering heads are described in DE 3015319 andDE 880576.

The gathering head (alternatively termed a loading shield) is forcedinto the material extracted from the deposit by the forward motion ofthe mining machine. There are two general approaches to facilitaterearward transport of the extracted material from the leading edge ofthe loading shield rearwardly onto the travel conveyor. Firstly, therotating cutting head boom may comprise helical discs extendinglengthwise along the boom to form an auger optionally coupled with asecondary helical conveying device that transports the materialrearwardly of the head. Example gathering heads configured with helicalaugers are disclosed in U.S. Pat. No. 3,860,291 and U.S. Pat. No.4,277,105 and with secondary helical augers as disclosed in WO2011/040806 and U.S. Pat. No. 4,952,000. An alternative approach tomaterial transport involves gathering arms or rotating discs provided atthe loading shield that require separate drive components. Such arms ordiscs are mounted at a base of the gathering head and operatecontinuously and independently of the cutting head. This gatheringmechanism is preferred over the helical cutting head configuration asthe latter approach hinders the torque force of the cutting teeth due tothe frictional contact with the extracted material that is drivenbetween the helical plates. A gathering head comprising rotatingspinning arms is disclosed in WO 98/03770 and U.S. Pat. No. 4,296,856.However, as will be appreciated the associated components and operationof rotating gathering arms increases the number of moving parts andweight of the machine generally ,which is disadvantageous formaintenance and transport reasons. Accordingly, what is required is agathering head effective to receive and transport rearwardly materialextracted from a deposit that addresses the above problems.

SUMMARY OF THE INVENTION

It is an objective of the present invention to provide a gathering headfor a continuous mining machine that obviates the need for additionalgathering or spinner arms drivably mounted at a base region of the headand that is effective to receive and facilitate rearward transport ofthe extracted material onto a conveyor or rearward transport assembly toconvey the extracted material away from the cutting face. It is afurther objective to provide a gathering head that requires little or nomaintenance and is generally lighter than conventional loading shieldassemblies.

The objectives are achieved by providing a material gathering shieldcomprising a plate-like construction in which the plates are arrangedspecifically to direct the flow of extracted material from a forwardmostor leading edge region of the head rearwardly towards a rearward exitregion from which material is then conveyed from the head. Inparticular, the present gathering head comprises a base extendinglengthwise along the head with a pair of sidewalls positioned at thelengthwise ends of the base. Each sidewall comprises a side surface tocontact the extracted material where these side surfaces are bothtapered inwardly in a widthwise direction of the head from the forwardend to the rearward end and are tapered outwardly relative to the basefrom a lowermost region to an uppermost region of each side surface.Accordingly, extracted material contacts the side surfaces and is guidedand deflected onto the base surface of the head and at least one backplate that extends upwardly from a rearward region of the base.Importantly, a width of the base of the head in a direction between theforward and rearward ends of the head is minimised, to reduce as far aspossible, the travel distance by which material must flow from theleading edge (of the head) to the exit region (conveyor). The declinedand inwardly tapering configuration of the sidewalls eliminates regionsof the head that would otherwise represent ‘entrapment zones’ whereextracted material could collect and represent an obstruction to thecontinuous flow of material through the gathering head.

The present gathering head also comprises a plurality of additional setsof conveyor feed plates that are also tapered and inclined to facilitatefurther the rearward transport of material along the loading shield.

According to a specific implementation of the present invention there isprovided a mining machine gathering head positionable at a forward endof a mining machine, the head having a forward end and a rearward end,the rearward end intended to be positioned adjacent the mining machine,the head comprising: at least one base extending lengthwise along thehead, the base having a base surface to contact material gathered by thehead; a pair of sidewalls positioned at the lengthwise ends of the base,the sidewalls each having a side surface to contact the material andbeing tapered inwardly in the widthwise direction of the head from theforward end to the rearward end; at least one back plate having amaterial contact surface extending upwardly from a rearward region ofthe base surface and extending in the lengthwise direction of thegathering head between the sidewalls; a ramp extending lengthwise alongthe head and being declined to project forward and downward from thebase to provide a leading edge at the head; characterised in that: eachside surface is tapered outwardly relative to the base surface from alowermost region to an uppermost region of each side surface to guidethe flow of material onto the base surface and the material contactsurface.

Preferably, the head further comprises a pair of side flanges eachflange being moveably mounted at an outer region of a respectivesidewall and capable of projecting forwardly of the respective sidewallto increase the inlet area of the gathering head when extended and tofacilitate manoeuvrability of the mining machine when retracted.Optionally, each flange is mounted at the respective sidewall via atleast one pivot mounting and at least one guide member to hold and guidethe pivoting movement of each flange relative to each sidewall.Preferably, each flange is pivotally driven by a power operated linearactuator such as a hydraulic or pneumatic cylinder to provide a simpleand reliable movement mechanism. Optionally, the guide member comprisesan elongate member slidably mounted within a guide bracket. Preferably,each flange is tapered inwardly and outwardly at substantially the sameangle as the side surfaces such that a flange contact surface (tocontact material gathered by the head) is substantially coplanar witheach respective side surface. This is advantageous to provide a smoothtransfer of material in the rearward direction over the head contactsurfaces.

Preferably, the head further comprises a conveyor having a beltprojecting rearwardly from the ramp, a forward end of the conveyorextending into a region of the base in the widthwise direction betweenthe sidewalls. Accordingly, this minimises the distance by whichmaterial within the head must travel rearwardly to reach the conveyor.Optionally, the head may comprise a helical auger projecting rearwardlyfrom the head to transport the extracted material rearwardly with suchan auger arrangement also projecting into the head region.

Where the machine comprises a conveyor, preferably a height level of thebase surface is positioned at a level above the belt to provide thatmaterial is configured to fall downwardly from the base surface onto thebelt. As such, the rearward flow of material through the head is greatlyfacilitated without the need for independently powered conventionalspinner or gathering arms.

Preferably, the head further comprises a first set of conveyor feedplates extending between and inclined downwardly from the base surfaceto the belt. Optionally, the head further comprises a second set ofconveyor feed plates extending between and being tapered inwardly fromthe back plate towards the belt. According to the specificimplementation, the first and second sets of feed plates comprise ashape configuration to match certain end edges of the base plate(s) andthe back plate(s). Preferably, a front end of the conveyor is positionedsubstantially at a region of the leading edge of the base and/or arearward edge of the ramp to facilitate the rearward travel of theextracted material through the head.

Optionally, the base comprises two base plates extending inwardly fromeach respective sidewall. Each base plate extends in the lengthwisedirection between a respective side wall and a region of the conveyor.Optionally, each base plate comprises a trapezium shaped profile where alongest edge of one of the parallel sides of the trapezium is positionedforwardmost to represent a leading edge of the base plate. That is, awidth of the base plate decreases from the leading edge to the rearwardedge of each plate. Such an arrangement functions to funnel the cutmaterial through the head towards the conveyor. Preferably, a shapeprofile of the side surface immediately adjacent each back plate andeach base plate comprises a generally triangular configuration to createthe present contoured contact surface of the gathering head to guidematerial from the forward end to the rearward end of the gathering head.

Preferably, the back plate comprises two back plates extending inwardlyfrom each respective sidewall and upwardly from each respective backplate. Optionally, each back plate comprises an upper shield plateprojecting upwardly from an upper edge of each back plate and beinginclined rearwardly and upwardly from each back plate. Accordingly, thecontact surface area of the head is increased to avoid sideways loss ofmaterial whilst facilitating directing of the material onto the conveyorvia the funnelling effect. Optionally, an approximate length of eachupper shield plate is approximately equal to a maximum length of eachback plate.

Preferably, the base surface is substantially planar and devoid ofobstructions to allow the unhindered passage of material gathered by thehead. Preferably, the head is devoid of rotatable spinner arms mountedat the base that would otherwise increase the weight, complexity andenergy consumption of the machine.

Preferably, a distance by which the base extends widthwise between theforward and rearward ends is less than a height of the head between alowermost to an uppermost region of the sidewalls. Such an arrangementfurther facilitates the funnelling of material rearwardly through thehead to maximise the travel distance of material by the rearward driveaction of the rotating cutting head.

According to a second aspect of the present invention there is provideda mining machine or a continuous mining machine comprising a gatheringhead as claimed herein.

BRIEF DESCRIPTION OF DRAWINGS

A specific implementation of the present invention will now bedescribed, by way of example only, and with reference to theaccompanying drawings in which:

FIG. 1 is a perspective view of a bolter mining machine configured formineral cutting with simultaneous bolting and mineral conveying in whichmaterial extracted from a deposit is initially gathered and transportedrearwardly by a forwardmost gathering head according to a specificimplementation of the present invention;

FIG. 2 is an external side elevation view of the mining machine of FIG.1;

FIG. 3 is an external front elevation view of the machine of FIG. 2;

FIG. 4 is a perspective view of the gathering head of the machine ofFIG. 3;

FIG. 5 illustrates schematically a side view of the gathering head ofFIG. 4 and the rotating cutting head of FIGS. 1 to 3 positioned at amaterial seam.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT OF THE INVENTION

The present gathering head will now be described with reference to apreferred embodiment by way of example mounted upon a bolter miner beingan electrically powered, track-mounted continuous mining machinedesigned to excavate roadways and install roof bolts simultaneously.Such mining machines comprise a series of cutter drums mounted on ahydraulically actuated frame to enable independent movement of the drumsrelative to a main frame and tracks. The machine also comprises roofbolters mounted on a stationary part of the main frame that can beoperated throughout the cutting cycle.

Referring to FIG. 1, the mining machine 100 comprises a main frame 101that provides support for an undercarriage or chassis 109 that supportsa pair of endless driven tracks 113 for propelling the machine 100 overthe ground and along a tunnel to advance forwardly through a materialdeposit seam. Main frame 101 comprises a generally forward end 102 and agenerally rearward end 103. A conveyor 104 extends substantially fromforward end 102 to rearward end 103 and is adapted to carry materialdislodged from the cutting face for subsequent discharge and stockpiling at a remote location optionally using additional conveying andmining apparatus. A movable cutting boom 105 is pivotally mounted at oneend 112 to main frame 101 via a pivoting bracket 110 and comprises asecond end 106 mounting a cutting head 115 that in turn mounts aplurality of rotatable drums 107. Cutting bits 108 project radially fromeach drum 107 and are specifically adapted to cut into and dislodge themineral material to be mined from the seam. Boom 105 and in particularend 106 is capable of being raised or lowered relative to main frame 101and endless tracks 113 to enable machine 100 to cut the seam face over avarying height range above the ground of the mine tunnel. Boom 105 isoperated by hydraulic rams 202 (referring to FIG. 2) and otherassociated components as will be appreciated by those skilled in theart.

A canopy 111 comprises a vertically uppermost region having a generallyplanar configuration and is adapted for being raised vertically upwardfrom frame 101 in a manner similar to cutting boom 105 so as to contactthe mine roof to provide structural support as necessary during thecutting and roof bolting operations. Additionally, a tail section 114projects rearwardly from the rearward end 103 of frame 101 to carryrearwardly conveyor 104 to a discharge end 116 representing arearwardmost part of the continuous miner 100.

Referring to FIGS. 1 to 4, the machine 100 further comprises a gatheringhead 117 mounted at forward end 102 via a head mounting bracket 203.Head 117 comprises a base 119 extending lengthwise along the head in adirection perpendicular to a main length of machine 100. Base 119 isterminated at each lengthwise end by a respective sidewall 120. A ramp118 is inclined downwardly from a forwardmost end of base 119 to providea leading and lowermost component of head 117. Ramp 118 extendslengthwise between sidewalls 120. Head 117 further comprises a backplate 124 projecting upwardly from a rearward region of base 119 that incombination with sidewalls 120, base 119 and ramp 118 represent the maincomponents of gathering head 117.

A pair of side flanges 121 are pivotally mounted at an outboard side ofeach respective sidewall 120 via a pivot mounting 204 located at anupper region 322 of head 117. An elongate guide bar 200 is mounted at alowermost region of each flange 121 at a lowermost end 323 of sidewalls120. Each flange 121 comprises a contact surface 303 alignedsubstantially coplanar with side surface 304 to effectively represent anextension of each sidewall 120. Accordingly, each flange 121 is capableof pivoting about mount 204 to swing forwardly and laterally outwardfrom the main components of shield 117 so as to effectively increase thecross sectional area of the mouth of head 117 that receives and gathersthe extracted material. Pivoting extension of flanges 121 is controlledvia a respective pair of power operated linear actuators 201 having afirst end mounted at sidewall 120 and a second end mounted at flange121.

Head 117 further comprises an initial transport conveyor 122 having aforwardmost end 310 located at a forwardmost region of head 117. Thatis, a region of conveyor 122 extends into base 119 and in a widthwisedirection between sidewalls 120. Conveyor 122 comprises a transport beltthat extends around a forward mounted guide and drive assembly 125positioned within a region of ramp 118. Conveyor 122 interfaces at itsrearward end with the main machine conveyor 104 that extends throughframe 101 and tale section 114.

Ramp 118 is substantially elongate to extend between sidewalls 120 andcomprises a leading edge 301 and a trailing edge 302. Ramp surface 300is inclined upwardly from front edge 301 to rear edge 302. According tothe specific implementation, base 119 comprise two base platespositioned to the left and right hand side of the conveyor 122 when head117 is viewed from the front as shown in FIG. 3. Each base platecomprises a base surface 324 for contacting material gathered by head117. The exposed base surface 324 comprises a generally trapezium shapedprofile such that the longest edge 311 of the parallel sides ispositioned forwardmost and immediately behind trailing edge 302 of ramp118. Surface 324 is further defined by an inner edge 314 and an outeredge 313 that extend rearwardly from ramp 118 to back plate 124. Eachedge 313, 314 tapers inwardly to a shortest rearward edge 312 alignedparallel with front edge 311. Outer tapering edge 313 is positioned incontact with a side surface 304 of side wall 120 whilst the secondinward tapering edge 314 is positioned opposed to conveyor 122.

As illustrated in FIG. 3, back plate 124 is divided into two plates thatextend upwardly from the rearward edge 312 of each respective base plate119. That is, a lowermost edge 325 of each back plate 124 is positionedat the rearward edge 312 of each base plate 119. A side edge 326 of eachback plate 124 is inclined upwardly from base edge 325 and is positionedin contact with side surface 304. An uppermost edge 327 of each backplate 124 forms a junction with a lowermost edge 319 of a respectiveupper shield plate 123 that is inclined upwardly and projects rearwardlyfrom each back plate 124. A rearward edge 320 of each shield plate 123represents a rearwardmost part of head 117 and acts to contact andfurther guide material flow onto the conveyor 122 that extends centrallybetween the corresponding pairs of base plates 119, back plates 124 andshield plates 123.

As illustrated in FIGS. 3 and 4, a relative height of each base surface324 is vertically above a height of the belt of conveyor 122 such thatas material is gathered by head 117 it falls or is guided downwardlyfrom surface 324 onto conveyor 122. This flow is facilitated by a firstset of conveyor feed plates 306 that extend between the lengthwise sidesof conveyor 122 and the inner tapering edges 314 of each base plates119. Each feed plate 306 comprises a guide surface 307 that is defined,in part, by a lengthwise edge 317 that is positioned in contact with theinner tapered edge 314. Feed plate surface 306 terminates at itsinnermost side by edge 318 positioned immediately adjacent the sideedges of conveyor 122. Due to the relative height difference betweenbase surface 324 and conveyor 122, each feed surface 307 is declineddownwardly from outer edge 317 towards inner edge 318. Material istherefore capable of sliding downwardly over surface 307 and ontoconveyor 122. The flow of extracted material onto conveyor 122 isfurther assisted by a second set of conveyor feed plates 308. Inparticular, a pair of second feed plates 308 are positioned inboard ofeach back plate 124 and a lower region of each shield plate 123. Inparticular, an outer edge 328 of each feed plate 308 is positioned incontact with the upstanding innermost edge 315 of each back plate 124adjacent each side of conveyor 122. Each feed plate 308 tapers inwardfrom its leading edge 328 to a rearwardmost edge 316 such that edge 316is positioned closest to conveyor 122 relative to leading edge 328.Accordingly, a feed surface 309 of each plate 308 provides a taperedguide surface from each back plate 124 to conveyor 122. The combinationof the first and second set of conveyor feed plates 306, 308 provide aguide mouth for conveyor 122 that tapers outwardly and upwardly tofacilitate transfer of material from the forwardmost edge 301 of ramp118 towards the main conveyor 104.

Each sidewall side surface 304 is inward facing towards back plates 124and base plates 119. Each side surface 304 is defined at its outermostregion by an outermost lengthwise edge 321 that extends upwardly fromlowermost region 323 to uppermost region 322. Each side surface 304 andin particular each sidewall 120 is tapered inwardly in the widthwisedirection of head 117 between a forwardmost region corresponding toleading edge 301 and a rearwardmost region corresponding to mount 205 ata rearward end of conveyor 122. That is, a width of head 117 decreasesgenerally in a direction from end 301 to end 205. Each side surface 304and sidewall 120 is also inclined rearwardly relative to a verticalplane and in particular a material contact surface 305 of each backplate 124. That is, each side surface 304 is inclined outwardly relativeto each base plate 119 and inclined rearwardly relative to each backplate 124. This configuration is advantageous to provide a guidedmaterial flow path as material flows over ramp 118 and into the maincollection area of head 117 in contact with each base plate 119, eachside wall 120 and each back plate 124. In particular, the material isboth deflected laterally inward towards conveyor 122 and upward ontoback plate 124 where it is subsequently directed onto conveyor 122 viarespective feed plates 306, 308.

As illustrated in FIG. 5, the present head 117 is configured such that asurface area of each base surface 324 is minimised as far as possible toavoid creation of ‘entrapment zones’ where the material flow wouldotherwise become static and disrupt the feed and gathering of head 117.This reduced surface area is achieved, in part, by the outwardly andrearwardly tapered sidewalls 120 that effectively project into the baseregion of head 117.

The surface area of each base surface 324 is further reduced via thefirst set of conveyor feed plates 306 being inclined downwardly relativeto each surface 324. Present head 117 therefore provides a greatlycontoured internal material contact surface formed from the plurality ofplate sections that are specifically angled relative to one another tooptimise the material flow. The need for independently powered gatheringor spinner arms is avoided due to this specific shape configuration ofhead 117 and in particular by minimising the distance between the frontand rear edges 311, 312 of each base plate 119. Accordingly, asillustrated in FIG. 5, a width of head 117 between leading edge 301 anda rearward side 501 of head 117 is less than a corresponding heightbetween lowermost and uppermost regions 323, 322. Accordingly, ascutting head 115 extracts material from seam 500, the fractured materialis capable of being transported over the respective surfaces 300, 324,304, 305, and 309 onto conveyor 122 by the action of the rotating head115. The present gathering head therefore is optimised for reducedweight and robustness by eliminating the additional componentsassociated with gathering or spinner arms conventional to existingcontinuous mining machines.

1. A mining machine gathering head positionable at a forward end of amining machine, the head having a forward end and a rearward end, therearward end arranged to be positioned adjacent the mining machine, thehead comprising: at least one base 0494 extending lengthwise along thehead, the base having a base surface arranged to contact materialgathered by the head; a pair of sidewalls positioned at the lengthwiseends of the base, the sidewalls each having a side surface to contactthe material and being tapered inwardly in the widthwise direction ofthe head from the forward end to the rearward end; at least one backplate having a material contact surface extending upwardly from arearward region of the base surface and extending in the lengthwisedirection of the gathering head between the sidewalls; and a rampextending lengthwise along the head and being declined to projectforward and downward from the base to provide a leading edge at thehead; wherein each side surface is tapered outwardly relative to thebase surface from a lowermost region to an uppermost region of each sidesurface to guide the flow of material onto the base surface and thematerial contact surface.
 2. The gathering head as claimed in claim hfurther comprising a pair of side flanges each flange being moveablymounted at an outer region of a respective sidewall and capable ofprojecting forwardly of the respective sidewall.
 3. The gathering headas claimed in claim 2 wherein each flange is mounted at the respectivesidewall via at least one pivot mounting and at least one guide memberto hold and guide the pivoting movement of each flange relative to eachsidewall.
 4. The gathering head as claimed in claim 2, wherein eachflange is tapered inwardly and outwardly at substantially the same angleas the side surfaces, such that a flange contact surface to contactmaterial gathered by the head is substantially coplanar with eachrespective side surface.
 5. The gathering head as claimed in claim 1,further comprising a conveyor having a belt projecting rearwardly fromthe ramp, a forward end of the conveyor extending into a region of thebase in the widthwise direction between the sidewalls.
 6. The gatheringhead as claimed in claim 5, wherein a height level of the base surfaceis positioned at a level above the belt to provide that material isconfigured to fall downwardly from the base surface onto the belt. 7.The gathering head as claimed in claim 5, further comprising a first setof conveyor feed plates extending between and inclined downwardly fromthe base surface to the belt.
 8. The gathering head as claimed in claim5, further comprising a second set of conveyor feed plates extendingbetween and being tapered inwardly from the back plate towards the belt.9. The gathering head as claimed in claim 5, wherein a front end of theconveyor is positioned substantially at a region of the leading edge ofthe base and/or a rearward edge of the ramp.
 10. The gathering head asclaimed in claim 1, wherein the base includes two base plates extendinginwardly from each respective sidewall.
 11. The gathering head asclaimed in claim 10, wherein the back plate includes two back platesextending inwardly from each respective sidewall and upwardly from eachrespective back plate.
 12. The gathering head as claimed in claim 1,wherein the base surface is substantially planar and devoid ofobstructions to allow the unhindered passage of material gathered by thehead.
 13. The gathering head as claimed in claim 1, being devoid ofrotatable spinner arms mounted at the base.
 14. The gathering head asclaimed in claim 1, wherein a distance by which the base extendswidthwise between the forward and rearward ends is less than a height ofthe head between a lowermost to an uppermost region of the sidewalls.15. A mining machine comprising: a forward end; and a gathering headpositioned at the forward end, the gathering head having a forward endand a rearward end, the rearward end arranged to be positioned adjacentthe mining machine, the gathering head including at least one baseextending lengthwise along the head, the base having a base surfacearranged to contact material gathered by the gathering head, a pair ofsidewalls positioned at the lengthwise ends of the base, the sidewallseach having a side surface to contact the material and being taperedinwardly in the widthwise direction of the gathering head from theforward end to the rearward end, at least one back plate having amaterial contact surface extending upwardly from a rearward region ofthe base surface and extending in the lengthwise direction of thegathering head between the sidewalls, and a ramp extending lengthwisealong the gathering head and being declined to project forward anddownward from the base to provide a leading edge at the gathering head,wherein each side surface is tapered outwardly relative to the basesurface from a lowermost region to an uppermost region of each sidesurface to guide the flow of material onto the base surface and thematerial contact surface.
 16. The mining machine of claim 15, whereinthe mining machine is a continuous mining machine.